JP2554098B2 - Thermal transfer recording medium - Google Patents

Description

The present invention relates to a novel thermal transfer recording medium. More specifically, the present invention relates to a thermal transfer recording medium suitable for applications requiring scratch resistance such as transfer of a bar code or a label transferred by a label printer or the like.

[Prior art and its problems] Barcodes are widely used as identification symbols or price display symbols for articles. Conventionally, this barcode has been formed by printing. However, recently,
Using a label printer dedicated to bar code transfer, etc., form a desired bar code on a predetermined label by thermal transfer,
The label to which the barcode has been transferred is often attached to a product and used. In this case, a special thermal transfer recording medium such as a barcode thermal transfer recording medium is not used, but a normal thermal transfer recording medium is used.

However, the bar code formed by the heat-sensitive transfer recording method using a normal heat-sensitive transfer recording medium is formed in a state in which the coloring material is uniformly dispersed in the binder component such as the heat-melting substance and the heat-softening resin. Therefore, it has a characteristic that it is softer than that formed by conventional printing. For this reason, the bar code formed by a normal thermal transfer recording medium may be scratched or colored by being contacted with other articles while being attached to the outside of the product packaging and being used. There is a problem that the material runs off the printed portion and contaminates the portion where the bar code is not formed, that is, so-called scumming occurs. Furthermore, when reading a bar code, the sensor may be scanned while in contact with the bar code, and even if such reading and scanning are repeated, the coloring material may stick out from the bar portion, causing scumming. is there.

In order to perform accurate identification using a bar code, it is necessary that the width of each bar is formed with an accuracy of a micron unit. Therefore, in a bar code formed by using an ordinary thermal transfer recording medium, a reading error frequently occurs due to a background stain caused by the protruding color material. That is, according to the study of the present inventor, when an article with a barcode formed by transfer using a normal thermal transfer recording medium is handled under normal conditions and then the barcode is read, the error occurrence rate is reduced. It turns out that it can reach as much as 30%.

On the other hand, when managing a product using a bar code or the like, a method of transferring the same bar code as the bar code attached to the product to a ledger and recording the same is used. In this case, conventionally, the method of transferring the same bar code twice has been adopted, but this method doubles the consumption of the thermal transfer recording medium and is uneconomical. Therefore, first, the bar code is transferred using the thermal transfer recording medium, and then the entire area is transferred using the part to which the bar code is transferred of the thermal transfer recording medium. A method of transferring a missing barcode (hereinafter sometimes simply referred to as “reverse transfer member”) is adopted.

However, since the bar code or reverse transfer member transferred by this method does not have sufficient scratch resistance as described above, a transparent seal prepared separately on the bar code or the reverse transfer member attached to the product, in particular. It was necessary to attach such items as protection.

[Object of the Invention] It is an object of the present invention to provide a heat-sensitive transfer recording medium capable of forming a transferred material having good scratch resistance and simultaneously making a transfer copy.

[Means for Achieving the Object] The structure of the present invention for achieving the object has a color heat-sensitive transfer layer in a heat-sensitive transfer-scheduled portion on a light-transmitting support, and the periphery of the color heat-sensitive transfer portion. The heat-sensitive transfer recording medium is characterized in that it has a colorless adhesive portion on a part of the light-transmissive support.

The heat-sensitive transfer recording medium of the present invention comprises a light-transmissive support, a color heat-sensitive transfer section laminated on a transfer-target portion of the support, and a light-transmissive support in the peripheral portion of the color heat-sensitive transfer section. And a laminated colorless adhesive part.

FIG. 1 schematically shows an example of the thermal transfer recording medium of the present invention.

In FIG. 1, the light transmissive support is shown at 11. A color heat-sensitive transfer section 12 is laminated on the planned transfer section on the light transmissive support 11. A colorless adhesive portion 13 is formed on the light-transmissive support 11 around the colored heat-sensitive transfer portion 12.
Are stacked.

—Support— The light-transmitting support in the heat-sensitive transfer recording medium of the present invention has a light-transmitting property such as transparent or translucent. Further, the light transmissive support may be colored within a range that does not impair its properties. Further, as such a light transmissive support, one having heat resistance strength, high dimensional stability and high surface smoothness is desirable.

As a material for forming such a light-transmissive support,
For example, polyethylene, polyethylene terephthalate,
Examples thereof include resin films such as polystyrene, polypropylene and polyimide.

Particularly in the present invention, it is preferable to use polyethylene terephthalate (PET). The thickness of the support is usually 60 μm or less in order to obtain good thermal conductivity, and in the present invention, those in the range of 1 to 15 μm can be preferably used, In particular, considering scratch resistance, transparency and thermal conductivity, it is particularly preferable to use one having a thickness in the range of 1 to 10 μm. When a light transmissive support having a thickness of less than 1 μm is used, the support is likely to be thermally deformed by the two heating operations of transfer onto the first transfer medium and thermocompression bonding onto the second transfer medium. Become. Further, in order to ensure good transparency and thermal conductivity, it is preferable that the thickness of the support is smaller than 10 μm.

The surface of the light transmissive support used in the present invention is subjected to surface treatment such as corona discharge treatment, glow discharge treatment, other electric shock victory, flame treatment, ultraviolet irradiation treatment, oxidation treatment and saponification treatment. It may be subjected to undercoating.

Further, the light transmissive support may have a backing layer on one surface.

-Colored heat-sensitive transfer part-The heat-sensitive transfer recording medium of the present invention has a color heat-sensitive transfer part in the transfer scheduled part on the above-mentioned light transmissive support.

The colored heat-sensitive transfer portion is usually a heat-softening layer containing a coloring material, a heat-melting substance and a thermoplastic resin, and is transferred to the transfer medium by being heated or melted by a line thermal head. And form an imagewise impression.

In the present invention, as the coloring material, pigments and dyes such as commonly used inorganic pigments and organic pigments can be used.

Examples of inorganic pigments include titanium dioxide, carbon black, zinc oxide, Prussian blue, cadmium sulfide and iron oxide, and chromates of lead, zinc, barium and calcium. Examples of organic pigments include azo-based, thioindigo-based, anthraquinone-based, anthranthrone-based, and triphenedioxazine-based pigments, vat dye pigments, phthalocyanine pigments, metal (eg, copper) phthalocyanine and its derivatives, and quinacridone pigments.

Examples of organic dyes include acid dyes, direct dyes, disperse dyes, oil-soluble dyes and metal-containing oil-soluble dyes.

Examples of heat-fusible substances that can be used in the present invention include carnauba wax, vegetable wax such as wood wax, auricury wax and espal wax, animal wax such as beeswax, insect wax, ceramic wax and whale wax, palmitic acid. Synthetic ester waxes such as cetyl, myricyl palmitate, cetyl stearate and myricyl stearate Paraffin wax, petroleum wax such as microcrystalline wax, polyethylene wax, ester wax and oxide wax, wax of mineral wax such as montan wax, ozokerite and ceresin , Higher fatty acids such as palmitic acid, stearic acid, margaric acid and behenic acid, palmityl alcohol, stearyl alcohol, behenyl alcohol, marganyl alcohol, myricyl alcohol And higher alcohols such as eicosanol, acetamide, amide propionic acid, palmitic acid amide, such as stearic acid amide and amide wax, and can include stearylamine, a higher amine such as behenyl amine and palmityl amine. These may be used alone or in combination.

Examples of thermoplastic resins that can be used in the present invention include ethylene copolymers, polyamide resins, polyester resins, polyurethane resins, polyolefin resins, acrylic resins, vinyl chloride resins, cellulose resins, and rosins. -Based resins, resins such as ionomer resins and petroleum-based resins, diene-based copolymers, natural rubber, styrene-butadiene rubber, elastomers such as isoprene rubber and chloroprene rubber, ester gum, rosin maleic acid resin, rosin phenol resin and hydrogenated rosin Rosin derivatives such as, and softening points of phenol resins, terpene resins, cyclopentadiene resins, aromatic hydrocarbon resins, etc. 50-150 ℃
The polymer compounds of

The thermoplastic resin preferably used in the present invention will be described below.

As the acrylic resin, for example, a monobasic carboxylic acid such as (meth) acrylic acid or an ester thereof,
An acrylic resin obtained by polymerizing at least one compound copolymerizable therewith with a known method such as emulsion polymerization can be used.

Examples of the carboxylic acid or its ester used at this time include (meth) acrylic acid, (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester,
Isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, amyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, (meta) ) Acrylic acid-2-ethylhexyl ester, (meth) acrylic acid decyl ester,
Mention may be made of (meth) acrylic acid dodecyl ester, (meth) acrylic acid hydroxyethyl ester and (meth) acrylic acid hydroxyethyl ester. Further, examples of the compound copolymerizable with the above-mentioned carboxylic acid or its ester include vinyl acetate, vinyl chloride, vinylidene chloride, maleic anhydride, fumaric anhydride, styrene, 2-methylstyrene, chlorostyrene, acrylonitrile, vinyl. Mention may be made of toluene, N-methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide, vinylpyridine and N-vinylpyrrolidone. These can be used alone or in combination of two or more.

Examples of the diene-based copolymer include diene-based monomers such as butadiene, isoprene, isobutylene, and chloroprene. Examples thereof include copolymers with the above-mentioned copolymerizable compounds. Specific examples of this copolymer include butadiene-styrene copolymer, butadiene-styrene-vinylpyridine copolymer, and butadiene-
Examples thereof include acrylonitrile copolymer, chloroprene-styrene copolymer and chloroprene-acrylonitrile copolymer.

Examples of the ethylene copolymer include ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-isobutyl acrylate copolymer, ethylene-acrylic acid copolymer. Examples thereof include a polymer, an ethylene-vinyl alcohol copolymer, an ethylene-vinyl chloride copolymer and an ethylene-acrylic acid metal salt copolymer.

Particularly in the present invention, it is preferable to use an acrylic resin. Further, as the thermoplastic resin, it is preferable to use a resin such as a petroleum resin which exhibits an adhesive force by heating.

The content of the coloring material in the color heat-sensitive transfer portion is usually 5
In the range of ~ 30% by weight. Further, the thermoplastic resin and the heat-fusible substance can be used in a content ratio within the range of 10 to 90% by weight, respectively.

The colored heat-sensitive transfer portion is usually laminated directly on the support, but it may be laminated via another layer such as a peeling layer or an adhesive layer, and a protective layer is further formed on this layer. Layers and the like may be laminated, and the colored heat-sensitive transfer portion may be composed of two or more layers.

Further, the colored heat-sensitive transfer portion may be laminated on the colorless adhesive portion described later.

The colored heat-sensitive transfer portion may include other substances contained in the heat-softening layer of a normal heat-sensitive transfer recording medium.

—Colorless Adhesive Portion— The thermal transfer recording medium of the present invention has a colorless adhesive portion in the peripheral portion of the colored thermal transfer portion.

The colorless adhesive part is a layer containing substantially no coloring material,
It is a layer having a function of heating and adhering the light-transmissive support on the second transfer medium.

Therefore, the colorless adhesive portion is a layer containing a heat-adhesive thermoplastic resin as a main component. However, in the present invention, the concept of "colorless" means that there is a difference in color tone to the extent that the barcode and this portion can be identified by a barcode reader, and, for example, Coloring of the colorless adhesive portion due to the color originally possessed by the component forming the colorless adhesive portion or discoloration of the component due to heating or the like during the production shall be included in the category of "colorless" in the present invention. .

As the heat-adhesive thermoplastic resin, it is possible to use the thermoplastic resin used in the above-mentioned colored heat-sensitive transfer portion, but among these, particularly good adhesiveness, acrylic resin, petroleum resin, modified polyethylene Resin, ethylene-vinyl acetate copolymer, synthetic rubber, polyamide resin, polyester resin and polyurethane resin are preferably used alone or in combination.

In the present invention, the above-mentioned thermoplastic resins can be used alone, but a heat-melting substance or the like can be added for the purpose of preventing blocking of the heat-sensitive transfer recording medium or adjusting the hardness of the colorless adhesive portion. . As the heat-fusible substance, the one used in the above-mentioned colored heat-sensitive transfer portion can be used. Then, in order to impart good heat adhesiveness to the colorless heat-sensitive transfer portion, the content ratio of these thermoplastic resins is preferably higher than the content ratio of the heat-melting substance in this layer. In particular, the content ratio of the heat fusible substance and the thermoplastic resin is 10:90 to 40:60 (more preferably 15: 8).
It is preferably within the range of 5 to 30:70).

-Preparation of heat-sensitive transfer recording medium-In the heat-sensitive transfer recording medium of the present invention, a material for forming a colored heat-sensitive transfer portion and a colorless adhesive portion is dissolved or dispersed in an organic solvent to prepare a coating liquid, and this colored heat-sensitive transfer recording medium is prepared. Part coating liquid on a light-transmissive support (solvent coating method), at least a part of the components for forming the colored heat-sensitive transfer part and the colorless adhesive part are heated and melted, and each is applied on the light-transmissive support. Of the heat-melted material (hot melt coating method), the material for forming the colored heat-sensitive transfer portion and the material for forming the colorless adhesive portion are dispersed in water to prepare an aqueous emulsion. It can be produced by a method such as a method of coating an aqueous emulsion for a colorless adhesive part on a light-transmitting support (water-based coating method). Further, the coating method of the colored heat-sensitive transfer portion and the colorless adhesive portion may be the same or different.

For example, as shown in FIG. 2, a method of applying a colorless adhesive portion 23 on the entire surface of the light transmissive support 21 and then applying a composition of the colored heat-sensitive transfer portion on the colorless adhesive portion 23 may be used. it can.

Colored thermal transfer part is dry thickness, usually 0.5 ~ 8.0μm
It is coated so as to be in the range of (preferably 1 to 4 μm). If it is thinner than 0.5 μm, adhesiveness and printing performance may be insufficient, and if it is thicker than 8.0 μm,
The sensitivity may decrease.

The colorless adhesive portion has a dry thickness of 0.2 to 8.0 μm (preferably 0.5 to 4) in consideration of adhesiveness and transfer performance.
It is preferable to apply it so that it falls within the range of (μm).

—Thermal Transfer Recording Method— The thermal transfer recording method using the thermal transfer recording medium of the present invention is usually performed as follows. First, for example, the thermal transfer recording medium obtained as described above is used to perform transfer onto the first transfer target medium. Usually, the first transfer medium is used for applications where scratch resistance is not so required, such as a recording ledger. Transfer to the first transfer medium can be performed by using an ordinary line thermal printer or the like. By thus performing the first thermal transfer on the first transfer medium, the thermal transfer recording medium is transferred. , The reverse transfer member remains.

FIG. 3a shows a transfer body formed by a usual method, and for example, a bar code as shown in FIG. 3a corresponds to the transfer body.

The heat-sensitive transfer recording medium of the present invention can be used in a method in which the light-transmissive support of the heat-sensitive transfer recording medium is heated and pressed at the same time when the reversal transfer body is transferred onto the second transfer medium.

Figure 3b shows the reverse transfer obtained by transferring the bar code shown in Figure 3a and then transferring the reversal transfer body remaining on the thermal transfer recording medium onto the second transfer medium. It is the body.

That is, the heat-sensitive transfer recording medium after the transfer to the first transfer medium is arranged so that the color heat-sensitive transfer portion faces the second transfer medium, and usually by heating while applying pressure, The light-transmissive support can be adhered onto the second transfer medium by using the colorless adhesive portion and the colored heat-sensitive transfer portion in the peripheral portion of the color heat-sensitive transfer portion as an adhesive. And
In the colored heat-sensitive transfer section that acts as an adhesive at the time of adhesion,
Since the pattern of the reversal transfer body is formed on the light transmissive support by the transfer to the first transfer medium, the reversal transfer body colored by the coloring material and the reversal transfer body are formed on the second transfer medium. The light-transmissive support is laminated on the second transfer medium by the transfer body and the colorless adhesive portion and acts to protect the reversal transfer body.

FIG. 4 shows a reversal transfer member transferred onto a second transfer target medium by using the heat-sensitive transfer recording medium of the present invention shown in FIG. 2 and a light-transmissive support adhered by the reversal transfer member. FIG.

In FIG. 4, the second medium to be transferred is designated by 20. A reverse transfer body (colored heat-sensitive transfer portion) 42 is laminated on the second transfer medium 41, and the light transmissive support body 41 is bonded using the reverse transfer body 42 and the colorless adhesive portion 43 as an adhesive layer. Has been done.

By using a label or the like having an adhesive layer on the back surface as the second medium to be transferred, the cut pieces cut into each bar code (reverse transfer body) can be attached to a product as a bar code.

Further, after the transfer on the first transfer medium, the thermal transfer recording medium may be cut into bar code units (reverse transfer member), and the obtained cut pieces may be heat-pressed onto the second transfer medium. . In this case, it is preferable to leave the colorless adhesive parts at both ends of the barcode or the like in the lengthwise direction and cut.
This is to improve the adhesiveness of the light transmissive support.

[Advantages of the Invention] According to the thermal transfer recording method of the present invention, a transfer body and a transfer body copy can be prepared at the same time. Moreover, since a new thermal transfer recording medium is not used for preparing the transfer body copy, the thermal transfer recording medium can be used very efficiently. Furthermore, since the original and the copy are in the relationship between the transfer body and the reversal transfer body, the occurrence of errors due to the malfunction of the apparatus is completely eliminated.

Further, since the surface of the reversal transfer member is protected by the light-transmissive support, it has very good scratch resistance, and the support of the thermal transfer recording medium which has not been used conventionally can be effectively used. You can

[Examples] In the examples and comparative examples shown below, the designation "parts" indicates "parts by weight".

(Example 1) A colorless adhesive composition having the composition shown below was applied to one side of a 6.0 μm polyethylene terephthalate film (PET) by a hot melt coating method using a wire bar so that the film thickness was 1.5 μm. And applied to form a colorless adhesive part.

Colorless adhesive composition: ethylene-vinyl acetate copolymer: 40 parts Petroleum resin: 20 parts Paraffin wax: 40 parts Next, a colored heat-sensitive transfer composition having the following composition was prepared.

Colored thermal transfer part composition Acrylic resin ...... 15 parts Petroleum resin ...... 25 parts Carbana wax ...... 40 parts Carbon black ...... 20 parts The composition obtained is coated on the above polyethylene terephthalate film (PET). Apply the hot melt coating method on the colorless adhesive part and apply 5 cm in the lengthwise direction, leaving 0.5 cm of unapplied parts on the edges as shown in Fig. 2, and then apply 2 cm of the unapplied part. The thermal transfer recording medium of the present invention was manufactured by repeating scanning provided and coating the colored thermal transfer portion.

The resulting thermal transfer recording medium was mounted on a prototype line thermal printer, and the barcode was transferred onto the first transfer target medium (storage mount). Then, the colored heat-sensitive transfer portion was cut at the central portion of the colorless adhesive portion not coated.

The color heat-sensitive transfer part of the obtained cut piece was superposed on the second transfer medium (label for sticking) so that the color heat-sensitive transfer part was in contact with the second transfer medium, and thermocompression bonding was performed at a temperature of 100 ° C.

The surface of the bar code formed on the sticker label was protected with a polyethylene terephthalate film (light transmissive support), and showed very good scratch resistance.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a thermal transfer recording medium of the present invention. FIG. 2 is a perspective view showing another embodiment of the thermal transfer recording medium of the present invention. FIG. 3a is a diagram showing a barcode which is an example of a transfer body. FIG. 3b is a diagram in which the reverse transfer body after the transfer of the barcode shown in FIG. 3a is transferred to the second transfer medium. FIG. 4 is a cross-sectional view of a reverse transfer body transferred onto a second transfer medium by the method of the present invention and a light-transmissive support adhered by the reverse transfer body. 11,21,41 …… Transparent support 12,22,42 …… Colored thermal transfer part 13,23,43 …… Colorless adhesive part 40 …… Second transfer medium

Continuation of front page (56) Reference JP-A-59-106996 (JP, A) JP-A-62-41061 (JP, A) JP-A-62-68770 (JP, A) JP-A-63-158289 (JP , A)

Claims (2)

(57) [Claims] 1. A colored heat-sensitive transfer layer is provided in a heat-sensitive transfer-scheduled portion of the light-transmitting support, and a colorless adhesive portion is provided on the light-transmitting support in the peripheral portion of the color heat-sensitive transfer. Thermal transfer recording medium. 2. The heat-sensitive transfer recording medium according to claim 1, wherein the light-transmissive support is a heat-resistant resin film having a thickness of 1 to 10 μm.